Tsc2 knockout counteracts ubiquitin-proteasome system insufficiency and delays photoreceptor loss in retinitis pigmentosa

Proc Natl Acad Sci U S A. 2022 Mar 15;119(11):e2118479119. doi: 10.1073/pnas.2118479119. Epub 2022 Mar 11.

Abstract

SignificanceStudies in multiple experimental systems have demonstrated that an increase in proteolytic capacity of post-mitotic cells improves cellular resistance to a variety of stressors, delays cellular aging and senescence. Therefore, approaches to increase the ability of cells to degrade misfolded proteins could potentially be applied to the treatment of a broad spectrum of human disorders. An example would be retinal degenerations, which cause irreversible loss of vision and are linked to impaired protein degradation. This study suggests that chronic activation of the mammalian target of rapamycin complex 1 (mTORC1) pathway in degenerating photoreceptor neurons could stimulate the degradation of ubiquitinated proteins and enhance proteasomal activity through phosphorylation.

Keywords: mTORC1; photoreceptor; proteasome; protein phosphorylation; retinal degeneration.

MeSH terms

  • Animals
  • Disease Models, Animal
  • Mechanistic Target of Rapamycin Complex 1 / metabolism
  • Mice
  • Mice, Knockout
  • Proteasome Endopeptidase Complex* / genetics
  • Proteasome Endopeptidase Complex* / metabolism
  • Proteolysis*
  • Retinal Rod Photoreceptor Cells* / metabolism
  • Retinal Rod Photoreceptor Cells* / pathology
  • Retinitis Pigmentosa* / genetics
  • Retinitis Pigmentosa* / metabolism
  • Retinitis Pigmentosa* / pathology
  • Tuberous Sclerosis Complex 2 Protein / genetics
  • Tuberous Sclerosis Complex 2 Protein / metabolism
  • Ubiquitin* / genetics
  • Ubiquitin* / metabolism
  • Ubiquitinated Proteins / metabolism

Substances

  • Tsc2 protein, mouse
  • Tuberous Sclerosis Complex 2 Protein
  • Ubiquitin
  • Ubiquitinated Proteins
  • Mechanistic Target of Rapamycin Complex 1
  • Proteasome Endopeptidase Complex